Merge pull request #316 from negativeExponent/update_fds_disk_handling

(fds.c) backport new fds disk handling

src/fds.c

@@ -82,6 +82,30 @@ static int32 DiskPtr;
 static int32 DiskSeekIRQ;
 static uint8 SelectDisk, InDisk;
 
+/* dec-12-19                                    */
+/* 4024(w), 4025(w), 4031(r) by dink(fbneo)     */
+/* remove this and old code after testing phase */
+#define USE_DINK
+
+enum FDS_DiskBlockIDs {
+	DSK_INIT = 0,
+	DSK_VOLUME,
+	DSK_FILECNT,
+	DSK_FILEHDR,
+	DSK_FILEDATA
+};
+
+static uint8  mapperFDS_control;    /* 4025(w) control register */
+static uint16 mapperFDS_filesize;   /* size of file being read/written */
+static uint8  mapperFDS_block;      /* block-id of current block */
+static uint16 mapperFDS_blockstart; /* start-address of current block */
+static uint16 mapperFDS_blocklen;   /* length of current block */
+static uint16 mapperFDS_diskaddr;   /* current address relative to blockstart */
+static uint8  mapperFDS_diskaccess; /* disk needs to be accessed at least once before writing */
+
+#define GET_FDS_DISK() (diskdata[InDisk][mapperFDS_blockstart + mapperFDS_diskaddr])
+#define FDS_DISK_INSERTED (InDisk != 255)
+
 uint32 lastDiskPtrRead, lastDiskPtrWrite;
 
 #define DC_INC    1
@@ -148,6 +172,16 @@ static void FDSInit(void) {
 	FDSSoundReset();
 	InDisk = 0;
 	SelectDisk = 0;
+
+#ifdef USE_DINK
+	mapperFDS_control = 0;
+	mapperFDS_filesize = 0;
+	mapperFDS_block = 0;
+	mapperFDS_blockstart = 0;
+	mapperFDS_blocklen = 0;
+	mapperFDS_diskaddr = 0;
+	mapperFDS_diskaccess = 0;
+#endif
 }
 
 void FCEU_FDSInsert(int oride) {
@@ -216,6 +250,7 @@ static DECLFR(FDSRead4030) {
 	return ret;
 }
 
+#ifndef USE_DINK
 static DECLFR(FDSRead4031) {
 	static uint8 z = 0;
 	if (InDisk != 255) {
@@ -232,6 +267,51 @@ static DECLFR(FDSRead4031) {
 	}
 	return z;
 }
+
+#else /* USE_DISK */
+
+static DECLFR(FDSRead4031) {
+	uint8 ret = 0xff;
+
+	if (FDS_DISK_INSERTED && mapperFDS_control & 0x04) {
+		mapperFDS_diskaccess = 1;
+		ret = 0;
+
+		switch (mapperFDS_block) {
+		case DSK_FILEHDR:
+			if (mapperFDS_diskaddr < mapperFDS_blocklen) {
+				ret = GET_FDS_DISK();
+				switch (mapperFDS_diskaddr) {
+				case 13:
+					mapperFDS_filesize = ret;
+					break;
+				case 14:
+					mapperFDS_filesize |= ret << 8;
+					/* char fdsfile[10]; */
+					/* strncpy(fdsfile, (char*)&diskdata[InDisk][mapperFDS_blockstart + 3], 8); */
+					/* printf("Read file: %s (size: %d)\n"), fdsfile, mapperFDS_filesize); */
+					break;
+				}
+				mapperFDS_diskaddr++;
+			}
+			break;
+		default:
+			if (mapperFDS_diskaddr < mapperFDS_blocklen) {
+				ret = GET_FDS_DISK();
+				mapperFDS_diskaddr++;
+			}
+			break;
+		}
+
+		DiskSeekIRQ = 150;
+		X6502_IRQEnd(FCEU_IQEXT2);
+	}
+
+	return ret;
+}
+
+#endif /* USE_DINK */
+
 static DECLFR(FDSRead4032) {
 	uint8 ret;
 
@@ -530,6 +610,7 @@ static DECLFW(FDSWrite) {
 			X6502_IRQEnd(FCEU_IQEXT2);
 		}
 	case 0x4024:
+#ifndef USE_DINK
 		if ((InDisk != 255) && !(FDSRegs[5] & 0x4) && (FDSRegs[3] & 0x1)) {
 			if (DiskPtr >= 0 && DiskPtr < 65500) {
 				if (writeskip)
@@ -541,8 +622,43 @@ static DECLFW(FDSWrite) {
 				}
 			}
 		}
+#else /* USE_DINK */
+		if (FDS_DISK_INSERTED && ~mapperFDS_control & 0x04) {
+
+			if (mapperFDS_diskaccess == 0) {
+				mapperFDS_diskaccess = 1;
+				break;
+			}
+
+			switch (mapperFDS_block) {
+				case DSK_FILEHDR:
+					if (mapperFDS_diskaddr < mapperFDS_blocklen) {
+						GET_FDS_DISK() = V;
+						switch (mapperFDS_diskaddr) {
+							case 13: mapperFDS_filesize = V; break;
+							case 14:
+								mapperFDS_filesize |= V << 8;
+								/* char fdsfile[10]; */
+								/* strncpy(fdsfile, (char*)&diskdata[InDisk][mapperFDS_blockstart + 3], 8); */
+								/* printf("Write file: %s (size: %d)\n"), fdsfile, mapperFDS_filesize); */
+								break;
+						}
+						mapperFDS_diskaddr++;
+					}
+					break;
+				default:
+					if (mapperFDS_diskaddr < mapperFDS_blocklen) {
+						GET_FDS_DISK() = V;
+						mapperFDS_diskaddr++;
+					}
+					break;
+			}
+
+		}
+#endif /* USE_DINK */
 		break;
 	case 0x4025:
+#ifndef USE_DINK
 		X6502_IRQEnd(FCEU_IQEXT2);
 		if (InDisk != 255) {
 			if (!(V & 0x40)) {
@@ -559,6 +675,55 @@ static DECLFW(FDSWrite) {
 			if (V & 0x40) DiskSeekIRQ = 200;
 		}
 		setmirror(((V >> 3) & 1) ^ 1);
+#else /* USE_DINK */
+		X6502_IRQEnd(FCEU_IQEXT2);
+		if (FDS_DISK_INSERTED) {
+			if (V & 0x40 && ~mapperFDS_control & 0x40) {
+				mapperFDS_diskaccess = 0;
+
+				DiskSeekIRQ = 150;
+
+				/* blockstart  - address of block on disk
+				 * diskaddr    - address relative to blockstart
+				 * _block -> _blockID ?
+				 */
+				mapperFDS_blockstart += mapperFDS_diskaddr;
+				mapperFDS_diskaddr = 0;
+
+				mapperFDS_block++;
+				if (mapperFDS_block > DSK_FILEDATA)
+					mapperFDS_block = DSK_FILEHDR;
+
+				switch (mapperFDS_block) {
+					case DSK_VOLUME:
+						mapperFDS_blocklen = 0x38;
+						break;
+					case DSK_FILECNT:
+						mapperFDS_blocklen = 0x02;
+						break;
+					case DSK_FILEHDR:
+						mapperFDS_blocklen = 0x10;
+						break;
+					case DSK_FILEDATA:		 /* <blockid><filedata> */
+						mapperFDS_blocklen = 0x01 + mapperFDS_filesize;
+						break;
+				}
+			}
+
+			if (V & 0x02) { /* transfer reset */
+				mapperFDS_block = DSK_INIT;
+				mapperFDS_blockstart = 0;
+				mapperFDS_blocklen = 0;
+				mapperFDS_diskaddr = 0;
+				DiskSeekIRQ = 150;
+			}
+			if (V & 0x40) { /* turn on motor */
+				DiskSeekIRQ = 150;
+			}
+		}
+		mapperFDS_control = V;
+		setmirror(((V >> 3) & 1) ^ 1);
+#endif /* USE_DINK */
 		break;
 	}
 	FDSRegs[A & 7] = V;
@@ -903,15 +1068,24 @@ int FDSLoad(const char *name, FCEUFILE *fp) {
 	AddExState(&FDSRegs[3], 1, 0, "REG4");
 	AddExState(&FDSRegs[4], 1, 0, "REG5");
 	AddExState(&FDSRegs[5], 1, 0, "REG6");
-	AddExState(&IRQCount, 4, 1, "IRQC");
+	AddExState(&IRQCount, 4 | FCEUSTATE_RLSB, 1, "IRQC");
-	AddExState(&IRQLatch, 4, 1, "IQL1");
+	AddExState(&IRQLatch, 4 | FCEUSTATE_RLSB, 1, "IQL1");
 	AddExState(&IRQa, 1, 0, "IRQA");
 	AddExState(&writeskip, 1, 0, "WSKI");
-	AddExState(&DiskPtr, 4, 1, "DPTR");
+	AddExState(&DiskPtr, 4 | FCEUSTATE_RLSB, 1, "DPTR");
-	AddExState(&DiskSeekIRQ, 4, 1, "DSIR");
+	AddExState(&DiskSeekIRQ, 4 | FCEUSTATE_RLSB, 1, "DSIR");
 	AddExState(&SelectDisk, 1, 0, "SELD");
 	AddExState(&InDisk, 1, 0, "INDI");
 	AddExState(&DiskWritten, 1, 0, "DSKW");
+#ifdef USE_DINK
+	AddExState(&mapperFDS_control, 1, 0, "CTRG");
+	AddExState(&mapperFDS_filesize, 2 | FCEUSTATE_RLSB, 1, "FLSZ");
+	AddExState(&mapperFDS_block, 1, 0, "BLCK");
+	AddExState(&mapperFDS_blockstart, 2 | FCEUSTATE_RLSB, 1, "BLKS");
+	AddExState(&mapperFDS_blocklen, 2 | FCEUSTATE_RLSB, 1, "BLKL");
+	AddExState(&mapperFDS_diskaddr, 2 | FCEUSTATE_RLSB, 1, "DADR");
+	AddExState(&mapperFDS_diskaccess, 1, 0, "DACC");
+#endif
 
 	CHRRAMSize = 8192;
 	CHRRAM = (uint8*)FCEU_gmalloc(CHRRAMSize);